I haven’t heard them yet, but based on HumbleHomemadeHIFI’s review, they rated the Miflex a 13+. My baselines are the excellent Intertechnik Audyn True Copper Max caps (12.5 rating) and the Jupiter Copper foil paper and wax caps (13.5 rating), so at the very least, these Miflex are worth a listen. I’d be interested in any feedback on these as well!

I’m wary of using bypass caps, especially in the signal path. Two parallel uneven paths of travel, wouldn’t that lead to some sort of smearing or slight phase issues with the sound? I dunno, never tried it.

I´ve replaced the originals coupling caps in the Yamamoto YDA-01 for Miflex Cu and the improvement was dramatic -I would say, night and day. There are two immediate and discernible effects: 1.- A decongested image, and 2.- The soundstage was bigger than ever. I´m still surprised how good a Hammond B3 organ can sound with its whole palette of colour nuances.

You know, I was always sceptical about a cap would bring such a dramatic improvement.

One last thing the Miflex are a bit more forward sounding compared to the originals.

If you press me to recommend them, I would say go ahead give it a try. In the end, they cost half than the Jupiters and way, way less than the Duelunds.

I think bypass caps are very much a touch and go thing. Truth is we don’t have a good understanding of why they sound the way they do.

It IS considered good engineering practice to bypass caps in circuits to achieve ideal capacitance. Low ESR and low inductance at the same time. Especially useful to be frugal and put a lot of Farads into small spaces, but these values alone don't really explain what I've heard in caps.

In speakers I’ve had very good luck bypassing 5uF and larger from Clarity with copper film caps. Really very very good.

However smaller Clarity caps have no benefit there. They seem pretty close to ideal.